More efficient planes and hybrid jet engines are just two of the advances NASA is working on. And that's not for spaceships, but for airplanes used for domestic flights.

Days after giving his State of NASA address, the space agency's top dog stepped into a wind tunnel where they're helping design the airliners of the future. "It would knock the socks off a Boeing 737. It'll cut fuel use by more than 50 percent," NASA administrator Charles Bolden said.

About 790 million of that will go to aeronautics research -- exactly what they're doing here at NASA Ames Research Center. "The increased funding will allow us to do something that NASA has not done in decades. That's to partner with industry to build a series of experimental aircraft or x-planes," Bolden said.

Bolden is a former astronaut who's flown four missions on the space shuttle, but it's this research on flight within Earth's atmosphere, where he thinks taxpayers could really feel the payoff from their investment in NASA. "A future where people can travel to most cities in the world in six hours or less in an airplane that can fly faster than the speed of sound, over land on biofuels," Bolden said.

Indeed, the research can also apply to space.

Now, they're testing the vehicles that could take humans to Mars.

However, by the time that happens, the number of people using commercial air travel here on Earth will have doubled.

Bolden said that means greener airplanes will be a necessity. "Investments in NASA's work today are investments in our children's tomorrow, our grandchildren's tomorrow, and our country's tomorrow and really our planets tomorrow," Bolden said.